Flightradar24 question
 

I was tracking a Bizjet with known registration but private destination and owner details. I predicted the destination but it disappeared off Flightradar24 completely. Would this suggest security precautions due VVIP flight?
Thanks

Maybe they turn off M-LAT or whatever under a certain altitude for their own reasons, whatever they may be ? I notice that certain aircraft are visible on some tracker, yet on others empty space. Who knows why, not me, but I'm sure someone will be along with a detailed explanation soon enough :-)

One of the most insecure systems ever invented.....

Tracking systems are a compete mystery to me. Remember being in Barbados a few years ago when FR 24 had some flights and Planefinder had others and some appeared on both. Never found out why.

Similarly last week in Madeira looking at Shipfinder, Cruise Ship Tracker and FleetMon to see what was coming into harbour and it was a compete arbitrary mix what appears on what tracker and occasionally 100,000 tones would appear with no warning at all.

Multilateration is progressively more difficult to achieve as altitude decreases, as it depends on the aircraft's transmissions being received simultaneously by several different ground stations, and that requires line-of-sight from each of them.

Are you talking about MLat? Or ADS-B/Mode S in general ?

ADS-B...

MLAT is great :)

Perhaps the jet landed at an airport not covered by a contributor to FR24. At Teesside airport a contributor turns his equipment off so aircraft disappear once they get to a certain height.

Fair enough.

In my experience ADS-B is pretty good, too, but if yours is mostly via FR24 I can understand your misgivings.

FR24 will block A/C info ( Mode-s hexcode, tail#, reg., owner/operator info, etc.) on request, but in this case, I think line-of-sight with a ground station was lost, which is very common in areas where there are sparse volunteer ground stations.

The other aircraft in the vicinity on the same route remained on screen until landing. That's why I was wondering if it was a security reason to hide the destination..

Thank you for your replies :-)

It's likely then (see explanations above) that the aircraft that remained on your screen was sending ADS-B data (and hence only needed to be picked up by one station on the ground to establish its position) and the aircraft that disappeared was only sending Mode S (and therefore could only be plotted while being picked up simultaneously by several ground stations).

Nothing to do with being blocked (in that case, FR24 wouldn't show the aircraft at all).

In my experience FR24 is not bad with passenger flights but poorer with biz jets and cargo flights. With the last flights often appear multiple times often with unknown against some of them. I don['t know if anyone knows what the problem is. It could be a lack of data from airline and airport sources and confusion with triangular (or more complicated) patterns where a sector may carry the number of the inbound or outbound flight.

FR 24 off line
 

The flight tracker seems to have gone off line this morning after slowing down, is it everyone watching Ukraine.

Unsurprisingly, it would appear so.

Thanks Dave, first finger pointed at Virgin, too many kids on the internet for school holidays, but no the speed test was ok.

The FAA have an option (LADD) for flight tracking data to be blocked on application, usually from owners of N-registered executive jets
Ironically, ADS-B, which states it does not block anything, has an LADD filter which allows the display of just these aircraft which are blocked by FR24 and other trackers.

When I looked a while ago Cloudflare was giving me a 7-minute waiting time for FR24 b before seeing the site and moments later I was blocked just like that! As mentioned they must be overwhelmed today as perhaps the most well known of the trackers.

ADS-B contains no built-in filters. Any aircraft transmitting ADS-B can be picked up by any ADS-B receiver within range. Or are you referring to filters at the flight trackers?

On the right hand side of the adsbexchange.com display there are a number of optional filters. One will restrict to military aircraft. Another "LADD" will only show aircraft blocked by FR24 etc. This filter will probably only show half a dozen aircraft over the whole of Europe.

Thanks for the clarification, makes sense now.